Dengue - Symptoms, Treatment, Vaccine

Dengue is a vector-borne tropical disease transmitted through mosquito bites. This seasonal disease peaks after the monsoon every year in India from July to November. The recent decade has seen an upsurge in Dengue cases in India and worldwide.

The species of mosquito responsible for transmitting Dengue is Aedes aegypti. The species also transmits chikungunya, yellow fever, and zika infection. It is a daytime mosquito that can fly up to a distance of 400 meters.

The virus causing Dengue is DENV, also called the Dengue virus. The four distinct types of the virus that cause Dengue are DENV-1, DENV-2, DENV-3, and DENV-4.

Dengue Status in India

• The WHO report estimates 390 million Dengue virus infections per year, of which 96 million manifest clinically.
• Dengue falls under the top 10 diseases prioritized by WHO for 2019 to 2024. This is because the incidence of Dengue has increased over 30 folds in the last five decades.
• One-third of the global burden of Dengue falls in India.
• India reported 1.64 lakh Dengue cases in 2021 against 2.05 lakh cases in 2020. The fatality rate has remained below 0.1% since 2019.
• The Government of India works towards Dengue control through the National Vector Borne Diseases Control Programme (NVBDCP). The program is administered by The National Center for Vector-Borne Diseases Control (NCVBDC). The program aims to prevent and control six vector-borne diseases, namely, Malaria, Kala-azar, Lymphatic Filariasis, Dengue, Chikungunya, and Japanese Encephalitis.

Factors Responsible for Dengue in India

• Urbanization, improper sanitation, open sewage, and poor town planning increase Dengue mosquitoes.
• An increase in temperature also increases the mosquito development rate.
• India provides a favourable climate for the breeding of these mosquitos. Hot weather, monsoon, and intermittent rainfall help these vectors sustain and spread diseases.
• India has low-skilled human resources for the prevention and control of the disease.
• Cases of Dengue are often under-reported due to political and other reasons.
• India lacks a planned approach to dealing with Dengue due to the coordination gap between health departments and local bodies.

Symptoms and Diagnosis of Dengue

• A sudden rise in temperature along with headache, weakness, rash, itching, and pain in bones, joints, and muscles are the common symptoms of Dengue.
• The extreme case of Dengue sees the rise of Dengue hemorrhagic fever with bleeding, low blood platelets, and plasma leakage.
• Dengue is diagnosed with a blood test. There is no specific medication to treat Dengue.

Dengue Control Methods Worldwide

• Dengue Vaccine

The U.S. Food and Drug Administration approved the Dengue vaccine called Dengvaxia or CYD-TDV in 2019. It is the first Dengue vaccine to get the regulatory nod in the U.S.

The vaccine is a live attenuated virus that triggers an immune response in the body. It is administered in people aged 9 to 16 with previously confirmed Dengue infections and living in endemic areas.

• Wolbachia Bacteria

A trial conducted in Indonesia showed that releasing mosquitoes with Wolbachia bacteria could successfully control the vectors from spreading Dengue. The mosquitoes are infected with Wolbachia bacteria and released in designated areas.

These infected mosquitoes breed with local mosquitoes until all mosquitoes have Wolbachia bacteria in them. The bacteria compete with the Dengue virus and make it harder to reproduce. As a result, the mosquitoes are less likely to spread Dengue.

FAQs on Dengue

Q.1. Which species of mosquito is responsible for transmitting the Dengue Virus?

The species of mosquito responsible for transmitting Dengue is Aedes aegypti.

Q.2. Which virus causes Dengue?

The virus causing Dengue is DENV, popularly called the Dengue virus.

Q.3. Which program of the Government works towards control of six vectors, including Dengue?

The National Vector Borne Diseases Control Programme (NVBDCP) works towards preventing and controlling six vector-borne diseases in India, including Dengue.

Q.4. Which Dengue vaccine was recently approved by the U.S. in 2019?

Dengvaxia, approved by the U.S. Food and Drug Administration in 2019, is the first approved vaccine for Dengue prevention.